[Orc][Modules] Fix Modules build fallout from a34680a33eb.
In a34680a33eb OrcError.h and Orc/RPC/*.h were split out from the rest of
ExecutionEngine in order to eliminate false dependencies for remote JIT
targets (see https://reviews.llvm.org/D68732), however this broke modules
builds (see https://reviews.llvm.org/D69817).
This patch splits these headers out into a separate module, LLVM_OrcSupport,
in order to fix the modules build.
Fixes <rdar://56377508>.
diff --git a/llvm/lib/ExecutionEngine/OrcError/OrcError.cpp b/llvm/lib/ExecutionEngine/OrcError/OrcError.cpp
index e6e9a09..5eab246 100644
--- a/llvm/lib/ExecutionEngine/OrcError/OrcError.cpp
+++ b/llvm/lib/ExecutionEngine/OrcError/OrcError.cpp
@@ -14,6 +14,8 @@
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ManagedStatic.h"
+#include <type_traits>
+
using namespace llvm;
using namespace llvm::orc;